enable disable field with checkbox

Trying to disable input fields and buttons with checkbox

HTML

<h4>Random or Not </h4>

<!-- Use Random Image -->  

<label><input name="o99_aufu_options[o99_aufu_random]" id="o99_aufu_options[o99_aufu_random]" value="1" checked="checked" type="checkbox">Use Random Image ? <em></em></label><br>  

<!-- If the above not checked - needs to be enabled -->                         
Upload Image <label for="upload_image"> <input id="upload_image" size="36" name="o99_aufu_options[o99_aufu_upload_image]" disabled="disabled" value="" type="text"> <input id="upload_image_button" value="Choose Image or upload" type="button" disabled="disabled"> </label>

JavaScript

jQuery(document).ready(function() {
    jQuery('input[name="o99_aufu_options\[o99_aufu_random\]"]').click(function(){
        var isChecked = jQuery(this).is(':checked') ;
        jQuery('#upload_image:input,#upload_image_button:button').attr('disabled', isChecked? 'disabled' : null);
    })
});